This invention relates to radio frequency identification devices, wireless communication systems, communication methods, methods of forming a radio frequency identification device, methods of testing wireless communication operations, and methods of determining a communication range.
Wireless communication systems including electronic identification devices, such as radio frequency identification devices (RFIDs), are known in the art. Such devices are typically used for inventory tracking. As large numbers of objects are moved in inventory, product manufacturing, and merchandising operations, there is a continuous challenge to accurately monitor the location and flow of objects. Additionally, there is a continuing goal to determine the location of objects in an inexpensive and streamlined manner. One way of tracking objects is with an electronic identification system.
One presently available electronic identification system utilizes a magnetic coupling system. Typically, the devices are entirely passive (have no power supply), which results in a small and portable package. However, such identification systems are only capable of operation over a relatively short range, limited by the size of a magnetic field used to supply power to the devices and to communicate with the devices.
Another type of wireless communication system is an active wireless electronic identification system. Attention is directed towards commonly assigned U.S. patent application Ser. No. 08/705,043, filed Aug. 29, 1996, incorporated herein by reference, and which describes such active systems in detail.
These systems include integrated circuit devices which include an active transponder and are intended to be affixed to an object to be monitored. The devices are capable of receiving and processing instructions transmitted by an interrogator. A device receives the instruction, if within range, then processes the instruction and transmits a response, if appropriate. The interrogation signal and the responsive signal are typically radio-frequency (RF) signals produced by an RF transmitter circuit. Because active devices have their own power sources, such do not need to be in close proximity to an interrogator or reader to receive power via magnetic coupling. Therefore, active transponder devices tend to be more suitable for applications requiring tracking of a tagged device that may not be in close proximity to an interrogator. For example, active transponder devices tend to be more suitable for inventory control or tracking.
It is often desired to determine or otherwise obtain the range of communications of a wireless communication system. For example, electronic identification systems may be installed in different environments, such as a variety of warehouse configurations, manufacturing plants, retail premises, etc. The communication range of an electronic identification system, or other wireless communication system, can be greatly impacted by the environment in which the system is utilized. Thus, it is often desired to determine the communication range of the system following implementation of the same in a particular environment and application.
This invention includes radio frequency identification devices, wireless communication systems, communication methods, methods of forming a radio frequency identification device, methods of testing wireless communication operations, and methods of determining a communication range.
According to one aspect of the present invention, a remote communication device includes a radio frequency identification device having a substrate and communication circuitry coupled with the substrate and configured to at least one of receive wireless signals and communicate wireless signals. Exemplary communication circuitry includes transponder circuitry operable to output return link identification signals responsive to receiving forward link wireless signals. Such forward link wireless signals can be outputted using an interrogator and the return link wireless signals can be outputted using the remote communication device.
The remote communication device preferably includes indication circuitry coupled with the communication circuitry and configured to indicate operations of the remote communication device and/or an associated interrogator. For example, the remote communication device can indicate at least one of receiving and generating of signals. The indication circuitry emits a human perceptible signal, such as a visible signal, in but one configuration to indicate operation of the remote communication device. The remote communication device of the present invention can be utilized in an exemplary application to assist with the determination of a communication range of the wireless communication system. Also, the remote communication device can be utilized to verify correct installation and operation of a wireless communication system, including antenna functionality, for example. Other aspects are provided in the present invention.